Derivatives of ascorbic acid having an antiscorbutic action and process for the manufacture of same



Patented ar- 7, 1939 UNITED STATES PATENT OFFICE DERIVATIVES OF ASCORBIC ACID HAVING AN ANTISCORBUTIC ACTION AND PMC- ESS FOR THE Kurt Warnat, Basel,

ACTURE F SAME Switzerland, asslgnor to Hoflmann-La Roche, Inc., Nutley, N. 1., a corporation of New Jersey No Drawing. Application February 8, 1938,

rial No. 189,444. In Germany April 24, 1937 'lClaims.

It has been found that by the action of aroyl halides on ascorbic acid, derivatives having an antiscorbutic action are obtained. This reaction most probably takes the following course;

0 o ('5 (i 110-!) H0--(|J Moo-Al R-0- J H +3RHal HC +Me-Hal 110- H RO'CH +2H-Hal.

H.011 CHQOQR l5 Me stands for hydrogen or alkali-metal, R comprises the benzoyl and substituted benzoyl radicals. The new compounds. are more stable to oxidising agents than ascorbic acid itself, so that they can be used for many purposes for. which ascorbic acid cannot be employed owing to its instability. They are indiflerent to iodine solution. By heating with caustic alkalis they are gradually hydrolysed. They are to be used medicinally.

Example 1 20 parts by weight of sodium ascorbate and 50 parts by weight of benzoyl chloride are heated to 60-80" C. When the condensation is completed, the reaction mass is treated with 100 parts by weight of warm water. The condensation product remains undissolved while unchanged The crude product is reascorbic acid dissolves. crystallised from dilute alcohol.. It crystallises in colorless flakes melting at 188-189 C. Benzoyl ascorbic acid is difllcultly soluble in cold and warm water, easily soluble in warm alcohol and slightly soluble in ether; In contrast to ascorbic acid it does not reduce iodine solution. The formula of this new compound is CaqHzoOo, which is proved by analysis Calculated, C 66.37% H 4.14%; Found, C 66.10% H 4.47%.

Example 2 10 parts by weight of sodium ascorbate are heated with 20 parts by weight of veratroyl chloride to 90--100 C. The reaction mass is then treated with water and the residue insoluble. in water recrystallised from alcohol. Veratroyl ascorbic acid, which is diilicultly soluble in alcohol, is obtained in needles which after having been dried sinter at 96-98 C. The compound is in- M diil'erent to iodine solution. but is hydrolysed by warm alakali. The formula of this new compound is Casi-132015, which is proved by analysis Calculated, C 59.27% H4.82% OCHs 27.84%; Found, C 59.20% H 5.10% OCH: 27.38%.

Example 3 20 parts by weight of ascorbic acid in 25 parts 1 v by weight of pyridine are treated with 45 parts by weight of benzoyl chloride at IO- C. The mass which solidifies in the cold is dissolved in 80 parts by weight of hot alcohol and cooled. Then 250 parts by weight of 5% hydrochloric acid are added and the aqueous layer removed. The

precipitated oil is dissolved in little alcohol from which, after a while, benzoyl ascorbic acid described in Example 1 is separated in crystalline form. It is recrystallised from alcohol or methyl alcohol and melts at 188-189 C.

Example 4 stances having the structure:

wherein R is a radical selected from the group consisting of benzoyl. and substituted'benzoyl radicals.

2. Benzoyl ascorbic acid having the structure:

C O 0-CH 1. A compound selected from the group of sub- 4. The process for the manufacture of a compound of the general formula OCH:

G Hos lie-(i RO-(BH HaOR wherein R is a radical selected from the group 25 consisting of benzoyl and substituted benzoyl' and its salts with a substance selected from the group or benzoyl and substituted benzoyl halides.

5. The process for the manufacture of a compound of the general formula C O 5 Kai l Ito-( RO-GH (IJHQOR wherein R is a radical selected from the group consisting of benzoyl or substituted benzoyl rad- 15 icals which comprises treating a substance selected from the group 01' ascorbic acid and its salts with a substance selected from the group consisting of benzoyl and substituted benzoyl halides in the presence of pyridine.

6. The process for the manufacture of benzoyl ascorbic acid which comprises heating a salt of ascorbic acid with benzoyl chloride.

7. The process of preparing benzoyl ascorbic acid which comprises treating ascorbic acid with benzoyl chloride in the presence of pyridine.

KURT WARNAT. 

